1. Field of the Invention
The present invention relates to a method of setting and applying design parameters of a data storage system, and more particularly, to a method of optimizing design parameters of a data storage system in which a failure of products caused by changes in the time required to use the products and characteristics of the products is pre-estimated, design parameters used in a signal processing circuit in the pre-estimated failure condition are optimized to be stored, and a signal is processed using the design parameters optimized in the pre-estimated failure condition when errors occur due to changes in conditions of use of the data storage system and a method of applying the optimized design parameters.
2. Description of the Related Art
In general, a failure necessarily occurs in all of parts that make up a system due to the passage of time and the use of the system. For instance, a coercive force of a storage medium changes in a hard disk drive, which is one type of data storage system, depending on the passage of time and the frequency of use. As a result, a magnetized signal is damped.
Also, the performance of a head is deteriorated by the repetitive use (read/write) of the head. The deterioration of the performance is not a problem in the early stage of the use of head, but causes a failure of the head as time passes. Such a deterioration makes an electrical signal inappropriate for use in a process of converting an analog signal stored in a storage medium into a digital signal that is user data. As a result, errors occur and, ultimately, a failure of the product is caused.
A conventional method of setting design parameters of a hard disk drive equally determines write current, read current, and various filter coefficients in a burn-in process having general test conditions. These coefficients have an important effect on a read characteristic of the hard disk drive and are optimized in a current state of each part. However, parts of the hard disk drive deteriorate over time.
Specifically, a read sensor, in charge of the read characteristic, has a shorter life than other parts. Thus, the shortened lifespan of the read sensor deteriorates the overall performance of the entire hard disk drive in a short time, thereby causing a failure of the hard disk drive. However, the design parameters fixed by the conventional method are unsuitable for accounting for the lifespan characteristic of the read sensor in which coefficients are changed due to the deterioration of the read sensor by the passage of time and the repetitive use of the system. As a result, it is impossible to optimize the system and, finally, a read error occurs and the entire system fails to process a signal.